Abstract

Anaphylaxis is a severe allergic reaction that can be rapidly progressing and fatal. In instances where the triggering allergen is not known, establishing the etiology of anaphylaxis is pivotal to long-term risk management. Our recent work has identified a novel IgE antibody (Ab) response to a mammalian oligosaccharide epitope, galactose-alpha-1,3-galactose (alpha-gal), that has been associated with two distinct forms of anaphylaxis: (1) immediate onset anaphylaxis during first exposure to intravenous cetuximab, and (2) delayed onset anaphylaxis 3–6 h after ingestion of mammalian food products (e.g., beef and pork). The results of our studies strongly suggest that tick bites are a cause, if not the only significant cause, of IgE Ab responses to alpha-gal in the southern, eastern and central United States. Patients with IgE Ab to alpha-gal continue to emerge and, increasingly, these cases involve children. This IgE Ab response cross-reacts with cat and dog but does not appear to pose a risk for asthma; however, it may impair diagnostic testing in some situations.

• Commins SP, Kelly LA, Rönmark E, et al. Galactose-α-1,3-galactose-specific IgE is associated with anaphylaxis but not asthma. Am J Respir Crit Care Med. 2012;185:723–30. Data are presented that show the specific IgE Ab response can contribute to total serum IgE and preliminary evidence that the alpha-gal epitope is not airborne in homes with or without cats or dogs, under conditions where large quantities of Fel d 1 and Can f 1 can be detected. The authors concluded that the association between IgE Ab and asthma relates to IgE Ab for protein allergens that are inhaled.PubMedView Article

•• Commins SP, James HR, Kelly LA, et al. The relevance of tick bites to the production of IgE antibodies to the mammalian oligosaccharide galactose-α-1,3-galactose. J Allergy Clin Immunol. 2011;127:1286–93.e1286. This study presents data related to tick bites inducing the IgE Ab response to alpha-gal. The report is the first example of a response to an ectoparasite giving rise to an important form of food allergy.PubMedView Article

• Prevention CfDCa. Approximate distribution of the Lone Star Tick, 2011. Available at http://​www.​cdc.​gov/​ticks/​maps/​lone_​star_​tick.​html. Edited by; accessed August 2012. Updated map that shows the expanding range of Lone Star Ticks in the US. The distribution of Lone Star Ticks now encompasses or includes 28 states.

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•• Morisset M, Richard C, Astier C, et al. Anaphylaxis to pork kidney is related to IgE antibodies specific for galactose-alpha-1,3-galactose. Allergy. 2012;67:699–704. The authors previously identified three cases of delayed anaphylaxis to mammalian meat and reported on skin testing with cetuximab. More recently, they have extended their work to study other foods including goat, horse, and particularly pork and beef kidneys, as a cause of severe delayed reactions in patients with IgE Ab to alpha-gal.PubMedView Article

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